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Unable to mount NFS datastore (1005948)

Symptoms

ESX/ESXi host cannot mount a NFS datastore
In the /var/log/vmkernel (ESX) or /var/log/messages (ESXi) log files, you see errors similar to:

Jun 15 13:01:39 esx-02 vmkernel: 2:13:51:38.221 cpu2:4287)WARNING: NFS: 201: Got error 13 from mount call
Jun 15 13:01:39 esx-02 vmkernel: 2:13:51:38.221 cpu9:4262)WARNING: NFS: 944: MOUNT failed with MOUNT status 13 (Permission denied) trying to mount Server (192.168.10.10) Path (/opt/esx-mounts)
In the vobd logs of the ESXi 5.0 host, you see the error:

[esx.problem.vmfs.nfs.mount.error.perm.denied] NFS mount <ip-address>:<mountpoint> failed: The mount request was denied by the NFS server. Check that the export exists and that the client is permitted to mount it.

Resolution

Note: You may see this issue if you have more than one vmkernel port on the same network segment. VMware recommends only having one vmkernel port per network segment unless port binding is being used. For more information on this recommendation, see Multi-homing on ESX/ESXi (2010877).

Taking the below example:

Checking the vmkernel port configuration we can see there are two vmkernel ports on the 10.1.1.0 network:

# esxcfg-vmknic -l

Interface Port Group/DVPort IP Family IP Address Netmask Broadcast MAC Address MTU TSO MSS Enabled Type

vmk2 Backup IPv4 10.1.1.23 255.255.255.0 10.1.1.255 00:50:56:7b:80:c8 1500 65535 true STATIC

vmk0 0 IPv4 10.1.1.33 255.255.255.0 10.1.1.255 9c:8e:99:fc:ed:ac 9000 65535

In the above example we want to use vmk0 for NFS connections (Jumbo Frames or MTU 9000 is enabled for this traffic).

Check the current routing tables to see which vmkernel port is the default for the 10.1.1.0 network.

# esxcfg-route -l

VMkernel Routes:

Network Netmask Gateway Interface

10.1.1.0 255.255.255.0 Local Subnet vmk2

192.168.55.0 255.255.255.0 Local Subnet vmk3

default 0.0.0.0 10.1.1.1 vmk2

From the above routing tables we can see that vmk2 is the default vmkernel interface for the 10.1.1.0 network and its currently being used for NFS traffic which is not desirable for the following reasons:

It is not predictable which vmkernel port will be used.
In our case the non Jumbo Frames vmkernel port is used which will result in lower performance.
The Access Control Lists (ACL) on the NFS server may not the IP address for vmk2 in the ACL thus it will refuse connection to the NFS export for this host.

If the host does not have two or more vmkernel ports on the same network use the following troubleshooting steps:

Ensure the NFS server supports NFSv3 over TCP. ESX/ESXi does not use UDP for NFS.
The NFS server must be accessible in read-write mode by all ESX/ESXi hosts.
The NFS server must allow read-write access for the root system account (rw).
The NFS export must be set for either no_root_squashor chmod 1777.
Ensure the ESX/ESXi VMkernel IP is allowed to mount the NFS share by inspecting the export list.
Ensure the mount is exported by running exportfs -ato re-export all NFS shares.
Check the following to ensure that the ESX/ESXi host is correctly configured to use an NFS share:
- Make sure that there is a vmkernel port group.
- Check the VMKernel IP address:
  1. Using the VI/vSphere Client, connect to Virtual Center/vCenter Server.
  2. Choose the ESX/ESXi host.
  3. Click the Configuration tab.
  4. Click Networking.
  5. View the Networking diagram for the VMKernel or click Properties > Ports > VMKernel. If VMKernel is not listed, you must add it.
- Check to see if the NFS server can be reached using vmkping.
- You can try to pinging the ESX/ESXi VMkernel IP from the NFS storage.

ESX Only

Check the following to ensure that the NFS service is ready to accept NFS connections from the ESX host.
Ensure NFS daemons are running on the server, using the command rpcinfo -p localhost or service nfs status:

# rpcinfo -p localhost
   program vers proto   port
    100000    2   tcp    111 portmapper
    100000    2   udp    111 portmapper
    100011    1   udp    925 rquotad
    100011    2   udp    925 rquotad
    100011    1   tcp    928 rquotad
    100011    2   tcp    928 rquotad
    100003    2   udp   2049 nfs
    100003    3   udp   2049 nfs
    100003    4   udp   2049 nfs
    100021    1   udp 60528 nlockmgr
    100021    3   udp 60528 nlockmgr
    100021    4   udp 60528 nlockmgr
    100003    2   tcp   2049 nfs
    100003    3   tcp   2049 nfs
    100003    4   tcp   2049 nfs
    100021    1   tcp 50217 nlockmgr
    100021    3   tcp 50217 nlockmgr
    100021    4   tcp 50217 nlockmgr
    100005    1   udp    949 mountd
    100005    1   tcp    952 mountd
    100005    2   udp    949 mountd
    100005    2   tcp    952 mountd
    100005    3   udp    949 mountd
    100005    3   tcp    952 mountd

# service nfs status
rpc.mountd (pid 2469) is running...
nfsd (pid 2466 2465 2464 2463 2462 2461 2460 2459) is running...

Additional Information

If you are using Lab Manager, do not set up NFS datastores through the VI Client on the ESX host. Unlike VMFS datastores, NFS datastores created through the VI Client are not recognized by Lab Manager. Such datastores conflict with the creation of NFS datastores through the Lab Manager Web console. For more information, see Error during the configuration of the host: NFS Error: Unable to mount filesystem (1003803).

Update History

05/13/2010 - Added ESX and ESXi 4.0 to Products 06/15/2011 - Added ESX only steps 02/16/2012 - Added ESXi 5.0 error in Symptoms

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